Delivery of halogens to a subterranean formation

Abstract

Compositions and methods for treating kerogen in a subterranean formation by generating bromine and other halogens in situ in a subterranean formation. In some implementations, the generation of the bromine or halogen is delayed. This can occur, for example, by the decomposition of precursors, a chemical reaction, the encapsulation of precursors or reactants, or a combination of these approaches.

What is claimed is: 
     
       1. A composition for treating kerogen in a subterranean formation, comprising:
 at least one of a bromate or chlorate salt, wherein the bromate or chlorate salt is encapsulated in a first polymer, and wherein the bromate or chlorate salt comprises a cation comprising a fluorine-carbon bond; and 
 an acid, wherein the acid is lactic acid, polylactic acid, chloracetic acid, citric acid, benzoic acid, or furoic acid. 
 
     
     
       2. The composition of  claim 1 , wherein the first polymer is a polymer matrix selected from a group consisting of polyvinyl butyral polymer, vinyl acetal polymers, butyral polymers, sytrene/-maleic anhydride copolymers, and alkylated vinylpyrrolidone copolymers. 
     
     
       3. The composition of  claim 1 , wherein the first polymer is an enteric coating and is selected from a group consisting of methylacrylate-methacrylic acid copolymers, cellulose acetate phthalate, cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, hypromellose acetate succinate, polyvinyl acetate phthalate, shellac, cellulose acetate trimellitate, sodium alginate, and zein. 
     
     
       4. The composition of  claim 1 , wherein the acid is encapsulated in a second polymer, wherein the second polymer is a polymer matrix selected from a group consisting of polyvinyl butyral polymer, vinyl acetal polymers, butyral polymers, sytrene/-maleic anhydride copolymers, and alkylated vinylpyrrolidone copolymers. 
     
     
       5. The composition of  claim 1 , wherein the acid is encapsulated in a second polymer, wherein the second polymer is an enteric coating selected from a group consisting of methylacrylate-methacrylic acid copolymers, cellulose acetate phthalate, cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, hypromellose acetate succinate, polyvinyl acetate phthalate, shellac, cellulose acetate trimellitate, sodium alginate, and zein. 
     
     
       6. The composition of  claim 1 , further comprising a fracturing fluid. 
     
     
       7. The composition of  claim 6 , wherein the fracturing fluid comprises a carbon dioxide based fluid or foam. 
     
     
       8. The composition of  claim 7 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium. 
     
     
       9. The composition of  claim 8 , wherein the first polymer is a polymer matrix selected from a group consisting of polyvinyl butyral polymer, vinyl acetal polymers, butyral polymers, sytrene/-maleic anhydride copolymers, and alkylated vinylpyrrolidone copolymers. 
     
     
       10. The composition of  claim 6 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium. 
     
     
       11. The composition of  claim 5 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium. 
     
     
       12. The composition of  claim 10 , further comprising a fracturing fluid. 
     
     
       13. The composition of  claim 4 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium. 
     
     
       14. The composition of  claim 13 , further comprising a fracturing fluid. 
     
     
       15. The composition of  claim 3 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium. 
     
     
       16. The composition of  claim 15 , further comprising a fracturing fluid. 
     
     
       17. The composition of  claim 2 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium. 
     
     
       18. The composition of  claim 17 , further comprising a fracturing fluid. 
     
     
       19. The composition of  claim 1 , wherein the cation is selected from the group consisting of [P(CF 3 ) 4 ] + , [N(CF 3 ) 4 ] + , and bis(tri(4-fluorophenyl)phosphine)iminium. 
     
     
       20. The composition of  claim 19 , further comprising a fracturing fluid.